Question

There are 100 students in a class.number of boy is 10more then the number girl.the average weight of boys is 50 kg and avarage weight of whole class in 45.5kg .the avarage weight of girls? (In kgs)

Answer 1

let no. of girls=x
therefore,no. of boys =x+10
total students=x+x+10
100=x+x+10
x=45.
x+10=55
average weight of boys=total weight of boys/no of boys
50=total weight of boys/55
2750=total weight of boys

average weight of all students =total weight of whole class/no of student
45.5=(total weight of boys+total weight of girl)/100
4550=2750+total weight of girls
total weight of girls=1800

average weight of girls=total weight of girls/no of girl
=1800/45
=40 kg